Designing a better circuit
What do smartphones, laptops, medical diagnostic equipment and the control units in your car have in common? They’re all based on semiconductors utilising the latest in innovative design and manufacturing processes. More specifically, most of these items are made from new materials and structures within the nanometre scale. Yet despite the many advantages such small-scale structures have, they are also prone to numerous problems, such as the overheating of integrated circuits and signal interference. The EU-funded NANOCOPS project aimed to arrest these problems before they even had a chance to manifest themselves in your new device. To accomplish this, the project developed algorithms and software tools capable of quantifying these undesirable effects and providing reliable validations of new nano-electronic designs. A toolbox for simulations One of the project’s core objectives was to create a meaningful and efficient circuit design capable of accommodating more and more devices on an increasingly smaller carrier surface, thus allowing more information to be transmitted interference free. ‘The underlying problem is that we have exhausted the physical limits of the carrier surface, forcing individual circuits and components to get closer and closer to each other – resulting in an increasing risk of the so-called crosstalk effect, which leads to unwanted electromagnetic interaction between individual components,’ says Project Researcher Dr E. Jan W. ter Maten. ‘This issue can no longer be ignored, especially as we continue to develop ever more powerful chips.’ The array of tools developed within the NANOCOPS project were specifically built to test these physical limits. For example, models and simulations were created to see just how far one can reduce an area while simultaneously increasing the number of components before experiencing adverse interactions. Another line of research used a combination of electromagnetic field and thermal simulations directly integrated into the chip simulation, allowing researchers to identify highly sensitive, interference-prone circuit components during the development phase. ‘What we found is that problems arise when electrical and thermal interactions affect the component, impacting the material stress and lifespan of transistors,’ says ter Maten. ‘It is therefore important to correctly assess heat generation to be able to develop more efficient and more durable transistors.’ More reliable predictions for better designs The NANOCOPS project resulted in a number of ground-breaking developments in nano-electronic design. For example, traditionally two separate operations were needed to simulate the dependence between high temperatures and extreme power levels in circuits. NANOCOPS researchers, however, and for the first time, successfully combined these two steps, speeding up the simulation and delivering significantly improved results. In the area of electromagnetic field simulation, the NANOCOPS tool can simulate not just individual components in 3D, but also the circuits themselves – allowing for all kinds of disturbance to be simulated and providing for a much faster detection of errors. Minimising the signal interference in smartphones and cardiac pacemakers, for example, requires the efficient simulation of various high-frequency signals of very distinct frequency. Here, electronic circuits, electromagnetic fields and heat evolution interact, and these factors – as well as the ageing of the devices themselves – cause changes that previously could not be predicted. ‘NANOCOPS and the various simulation tools that the project developed changed all of this,’ concludes ter Maten. ‘Manufacturers can now base the design of their integrated circuits on reliable predictions, thus improving their operability, efficiency and lifespan.’
Keywords
NANOCOPS, nano-electronic design, circuits, integrated circuits, smartphones, pacemakers
